Combine the oatmeal and orange juice. Set aside. In a large mixing bowl, combine flour, baking powder, salt, soda and sugar. Make a well in the center of the dry ingredients and add oatmeal mixture, oil and eggs. Stir only until ingredients are moistened. Carefully fold in berries and orange peel. Spoon batter into greased muffin tins, filling about 3/4 full. Combine walnuts, sugar and cinnamon. Sprinkle over muffins and bake at 400 degrees F for 15 minutes or until muffins test done. Remove from tins and the blueberry muffin recipe with orange is ready to serve warm...Enjoy it !blueberry-muffin recipe.